The invention pertains to a conveyor chain for the movement of objects.
Conveyor chains are known which are used in industry for the conveyance of different objects. Such conveyor chains consist of numerous chain links, which as a rule have a planar surface, on which the objects to be conveyed can be placed. Frequently, at least two conveyor chains, which are parallel to each other, are used so that larger objects can be moved, which in this case rest on both chains. The individual chain links are moveably connected with each other so that pivoting movements in two mutually vertical directions are possible. On the one hand, the chain links must be able to move on the transport plane with respect to each other, so that the course of the conveyance is also possible in curves, on the other hand it must be possible that the chain links can move vertically to the transport plane so that a return of the chain links beneath the conveyance plane is possible. In the known conveyor chains, this movement that is moveable around two axes is formed between the chain links by a type of universal joint, i.e. the two pivoting axes intersect in a point. This link connection is constructed in such a manner, that the individual chain links are connected with each other by pivoting axes, which are horizontal or parallel to the transport plane, which allow a pivoting movement vertical to the transport plane. These pivoting axes are firmly attached to a first chain link, while in the second neighboring chain link they are located in elongated holes, which permit not only a pivoting movement of the two chain links around these axes with respect to each other, but also provide the axis with an additional freedom of movement in the direction of the transport plane, which allows a pivoting movement of the chain links within the transport plane. Indeed, only a real pivoting axis exists; the pivoting movement around the second, not actually present pivoting axis is merely achieved by means of a play in the orientation of the first axis in one of the two adjacent chain links. According to this construction, only limited movement is possible in the known conveyor chains. Furthermore, dirt can easily collect in the lateral elongated holes that contain the pivoting axes, which can additionally restrict movement and thus the function of the conveyor chain. The limited movement of the known conveyor chains requires additionally a large play in the lateral guide in order to enable a course in curves.
The task of the invention is to create an improved conveyor chain that allows greater mobility.
This task is resolved by the characteristics cited in claim 1. Preferred designs can be derived from the subclaims.
The conveyor chain according to the invention includes for the two required pivoting movements two separate hinges between the individual chain links, which are connected by means of corresponding connecting links. The uncoupling of the two pivoting axes allows a greater freedom of movement of the chain links around the individual axis. In addition, the lateral elongated holes known from conventional technology, which are extremely sensitive to dirt, can be omitted, which results in an improvement of the reliability of the function of the conveyor chain. In the case of the conveyor chain according to the invention, the movement of the chain links with respect to each other is no longer limited by the construction of the links themselves, as is the case with the known conveyor chains, but merely by the eventual stops which are the result of the shape of the upper and lower surfaces of the main links.
Advantageously, the connecting links are almost completely covered at the upper and lower surfaces by at least one adjacent main link. This has the advantage, that an almost continuous, smooth surface is formed on the upper surface of the chain, which is interrupted only by a narrow gap between the individual main links. This allows a large supporting surface for the goods to be transported and the hinges between the individual chain links are protected against the effects of dirt or mechanical damage by the cover. The cover of the connecting links on the lower surface allows an almost continuous, smooth supporting surface for the conveyor chain, which improves the sliding characteristics of the chain in a guide.
Preferably, a connecting link is covered on its upper and/or lower surface up to the area of the first hinge by a main link adjacent to the second hinge. Such a design has as its effect that despite the almost complete coverage of the connecting link the movement of the two main links parallel to the chain surface is virtually not restricted. In addition, the movement between the main links vertical to the chain surface or to the transport plane is virtually not restricted, since the parting line between the upper and lower surfaces of the two adjacent main links lies in the area of the second hinge. Thus the two hinges are optimally protected, without significantly restricting the movement of the conveyor chain.
All main links and all connecting links preferably have the same design. This allows a cost-effective construction of the conveyor chain, since it consists only of two different components, the main links and the connecting links.
Preferably, the main links contain recesses on their lower surface, in which the chain wheel can engage. These recesses on the lower surface can be designed, independent of the remaining design of the conveyor chain, in such a manner that an especially favorable contact between the chain wheel and the main links is achieved. This results in reliable and secure propulsion of the conveyor chain, over which large forces can also be transmitted reliably, so that heavy goods can also be transported on the conveyor chain.
Preferably, the main links also include lateral guide grooves, which run in the direction of the longitudinal direction of the chain. These guide grooves allow a secure movement of the conveyor chain in a corresponding conveyance profile. Advantageously, the guide grooves are designed in such a manner that the upper surface of the conveyance profile is covered by the upper flanks of the guide groove, especially also in curves. This prevents, that dirt or also parts of the goods being conveyed can attach to or be caught between the conveyor chain and the conveyance profile. Thus, together with the conveyance profile, the conveyor chain constitutes a smooth, almost closed surface, which prevents the penetration of foreign bodies in the conveyance trajectory and thus potential functional disturbances. Furthermore, the formation of such a groove may also have as effect, that the main links rest both with the upper flank of the guide groove as well as with their lower surface on the conveyance profile, which may result in an enhanced supporting capacity.
Preferably, at least one of the two hinges consists of several comb-like protrusions on the main link and corresponding comb-like protrusions on the connecting link, which mesh in the spaces of the protrusions on the main link, whereby a traversing hinge bolt passes through the protrusions of the main and connecting link. This design of the hinges ensures that the hinge bolt receives multiple support on the connecting link as well as on the main link, which ensures the reliable transmission also of larger forces. Furthermore, the force transmission is extremely uniform because of the multiple support of the hinge bolt.
The hinge bolts are preferably retained in the hinges by means of catch connections. This allows a simple mounting of the conveyor chain, since the hinge bolts merely must be inserted in the corresponding openings of the hinges and then lock in them. Thus, no additional attachment elements and attachment processes are required.
Preferably the hinge bolt is made of synthetic material. This will preclude corrosion of the hinge bolt, which would impede the movement of the hinge. Also, a hinge bolt, especially a hinge bolt with catch connections, can be manufactured very cost effectively and easily from synthetic material.
Preferably, the main links and/or the connecting links are manufactured in one piece, preferably from synthetic material. The single-piece design of the individual links reduces the number of required mounting activities and therefore allows a faster and more cost effective mounting of the conveyor chain. In addition, the reduced number of parts limits the number of potential failures and thus enhances the reliability of the conveyor chain. The main and the connecting links can easily and cost effectively be manufactured from synthetic material and additionally, the use of synthetic material precludes corrosion of the conveyor chain which may affect its function.